It is generally known to arrange storage compartments on the floor of an aircraft cabin next to passenger seats. Such compartments are provided, for example, on the upper deck of the Boeing passenger aircraft B 747.
It is also generally known to provide ventilation air channels in aircraft cabins for supplying fresh air or venting exhaust air, through air vents or openings on each deck. The cross-sectional flow area of these openings is too small, however, to provide an adequate pressure equalization in the case of an explosive pressure drop or decompression. For this reason, dado panels with decompression flaps are arranged in almost all aircraft that have pressurized cabins. These panels provide with their normally covered openings or air vents a larger cross-sectional flow area between the decks of an aircraft in case of an explosive decompression, thereby ensuring a rapid pressure equalization between the decks.
U. S. Pat. 4,383,666 (Allerding et al.) discloses a safety mechanism for aircraft having separate cabins on separate decks separated by an intermediate cabin floor. The cabins are pressurized during flight at high altitudes. Air passages that allow air flow between the upper and lower cabins are arranged in peripheral areas in the upper cabin floor. These air passages are enclosed on the upper floor with panels or covers provided with air vents. The panels are fixed in their respective positions by a self-actuating locking mechanism. Each of the panels comprises two pivotable or tiltable flaps with a space between the flaps. The flaps are movable relative to each other. The outer flap faces the air passage in the cabin floor and the inner flap faces the upper cabin. The outer flap is constructed as a self-actuating releasable rigid locking mechanism for releasing the inner flap from its locked position during a suddenly occurring pressure drop, allowing both flaps of a panel to fold back toward the outer wall of the aircraft, thereby allowing free passage of air between the upper and the lower cabins. There is room for improvement because conventional structures do not efficiently use the available space near the cabin floor especially next to the curved cabin wall.